I am really impressed with the amount of information there is on this board about the CA160s. My gradfather gave me his old '67 a few years back which I have just started playing around on to try and get running. One problem I'm having is that I can't locate the frame serial number. It is going to be challenging to register here in Colorado without the s/n. I understand it should be on the left side near the rear of the tool box - correct?

I will post pictures later of the areas I've gone to town with paint stripper on.

Glad to have ya around Matt. The serial number stamped into the frame is found by removing the left side frame cover. Maybe someone put some really thick paint on it and covered it up? The left cover is the one you remove to get to the air filter which is located inside the frame. It should be pretty easy to see as long as it's not covered up with paint that is.

Glad to have ya around Matt. The serial number stamped into the frame is found by removing the left side frame cover. Maybe someone put some really thick paint on it and covered it up? The left cover is the one you remove to get to the air filter which is located inside the frame. It should be pretty easy to see as long as it's not covered up with paint that is.

Yeah, there's nothing visible through the paint under that cover. The strange thing is it doesn't seem like anyone has touched the paint on the bike since it was new, so I'd expect to find it fairly easily. What area under the cover should I focus my search? It seems like I heard bottom right somewhere...

Yes, someone sanded off the serial number. Although there is some hope. Some states like MN use the engine number to register the bike. If you have a title and the title shows the frame number, then it could be an issue. You can try an experiment that worked for me on my current project, that was extremely rusty in that area and the number was impossible to read.

Wet sand the serial number area with 400 paper until smooth. Apply instant gun blueing (found at Wallmart) two or three coats until the metal is dark blue. Then polish the blue area with 0000 steel wool. Use a flashlight at an angle and look closely. You might just be able to catch a glimpse of the number.

Here in CA I'm sure I could go to the DMV and get a title for it with a little work. I'm positive they just give you a form to write down your statement on what happened to the VIN and the history of the bike. Then they would probably send me to the Highway Patrol who does the official VIN inspections. I have seen them affix new VIN plates to frames and issue a new title to the owner. I would HEAVILY stress to anyone you talk to that the VIN was sanded off accidentally with a power sander along with the rest of the frame. They are VERY shallow when they are stamped and you could probably print out a picture of a comparable VIN stamp from one of our bikes to take in with you. They are easy to mess up when you are sanding. Because they are so shallow and the lettering is old school and hard to read they often make me go to the station to get it verified.

In your case I would just go to your local DMV office and tell them you sanded off the numbers from the frame while getting it ready for paint. WOops! It happens. Then ask them where to go from there. You've had it in the family forever so it just fell out of the system. Tell them the history of it and they will likely ask you to write it down on a form and then visit the local law enforcement that handles the stolen VINs and VIN verifications and what not. It's a good idea to have the breakdown of what the VIN numbers and letters mean. I think it's in the manual somewhere. That way if they have any questions about the original VIN configuration you can provide that. They will likely give you a completely new updated VIN though. I just would have all my ducks in a row to make things go smoothly. It can be done on classic stuff like this.